


Of Flowers and Fatal Love

by natsa



Category: Black Clover - Tabata Yuki (Anime & Manga)
Genre: Alternate Universe - Canon Divergence, Hanahaki Disease, M/M
Language: English
Status: In-Progress
Published: 2020-09-08
Updated: 2020-09-25
Packaged: 2021-03-06 20:40:31
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 4,626
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26355127
Author URL: https://archiveofourown.org/users/natsa/pseuds/natsa
Summary: When did his feelings for Yuno start to shift? When had the feelings he harbored for his best friend changed into something not purely platonic, but instead romantic? Asta didn’t know. In fact, he didn’t even realize anything was wrong until the first blood-soaked flower petal fell from his lips.
Relationships: Asta & Yuno (Black Clover), Asta/Yuno (Black Clover)
Comments: 34
Kudos: 151





	1. Love At First Cough

**Notes for the Chapter:**

> Too many ideas. Not enough motivation. Thanks to my followers on Instagram who gave me this idea. Bless your souls for all your love and support.

It all started after his mission with Luck and Noelle to the magic dungeon.

Though, if Asta was being honest with himself, it probably began much sooner. Perhaps it started when he and Yuno first made their promise as kids. Maybe even before then, but Asta was never good at picking up on the pieces to puzzles he didn’t know existed.

He had been so close to death in their battle with Mars and, quite frankly, he had thought he  _ was  _ dead. Asta was sure he would be killed in battle trying to protect the people around him. Turns out, funny stuff happens to you when you think your life is about to end.

You start replaying old memories in your head and think stuff like  _ “Did I really make the most out of my time being alive?”  _ and  _ “What was this all for?” _ . It was the most introspective thought Asta had ever had. He wasn’t much of a thinker, preferring to tackle life head-first and ask questions later, but right then all he could do was question his very existence.

In those moments of uncertainty, when he was being healed and the teams from both the Golden Dawn and the Black Bulls worked together to escape the collapsing fortress, Asta thought of the answers to those questions and tried to figure out what his life had meant to the world.

His life up until then seemed like an introduction of sorts. A prelude to the actual story he wanted to tell. Most of his childhood and teen years had been spent training. He was always so focused on his dream, and he honestly couldn’t say he regretted any of the hard work that led up to this point. If he hadn’t spent all that time and effort training regardless of the odds, then he probably wouldn’t have experienced the joy of becoming a Magic Knight. He also probably wouldn’t be this close to death, but you can never really know for sure.

Lying there on a whirlwind of Yuno’s magic, watching as huge pieces of rock fell from the ceiling and began to fill the interior of the dungeon with dust and rubble, Asta felt nothing but contentment with the choices he had made. If he were to die now, his only regret would be that he didn’t live long enough to fulfill his promise with Yuno. 

Then, like a dam bursting forth a million pounds of water, Asta’s head was flooded with unrelenting thoughts about  _ Yuno _ .

Almost all of his life was dedicated to his promise with Yuno. Everything he had done, every goal Asta set for himself, it was all in hopes of one day proving that the impossible was possible and that status didn’t matter in the face of hard work and perseverance. It was something he desperately wanted to prove to Yuno when they were kids. Back when his best friend cried when he tripped and thought he was weak, Asta wanted to prove that even kids like them could make something of themselves if they tried hard enough.

Yuno encompassed so much of who Asta was and what he wanted to accomplish. It was hard to believe Asta had never noticed until that point. Now, being a little bit older, Asta was awestruck by just how much he valued Yuno. Yuno’s opinion was the only one that mattered. Yuno’s smile was the only one that held any meaning behind it. Yuno’s unwavering belief in him was the only support Asta needed to hold his head up high in a world which only looked down on him.

Everything was for Yuno.

Asta’s eyelids felt heavy and his ears were ringing from all the debris crashing to the ground below, but his mind felt clearer than ever. He willed his eyes to stay open and tilted his head slightly to stare at the very person invading his thoughts. In his dazed state of pain, Asta’s eyes were clouded over, like the windows of a house after an especially cold night. However, when he really concentrated, he could make Yuno’s face come into focus.

For what felt like the first time in his life, Asta looked at Yuno and  _ really  _ looked, seeing exactly what his best friend truly meant to him and not just Yuno himself. 

He saw the boy he inadvertently devoted his life to. He saw a person who he’d do anything for. He saw someone he wanted to be acknowledged by. He saw a life companion.

He saw the person he loved most in this world, but he also saw someone utterly unobtainable. 

Yuno was perfect in every way imaginable. He was smart, talented, and charismatic. The exact opposite of Asta. Sure, they were rivals, and he knew Yuno since the day he was born, but did that give him the right to love someone so amazing when he himself was so mediocre in comparison? Asta felt his chest tighten up and this time, when searing pain seized his whole body and he could no longer focus on Yuno's face, he let his eyelids shut.

Asta coughed. He thought nothing of it. The amount of dust being kicked up as they came out of the dungeon was unreal and he had a literal hole in his abdomen, so he wrote it off as nothing but a tickle in the back of his throat.

What a fool he had been.

**Notes for the Chapter:**

> Tell me what you guys think below please! Feedback motivates me to no end.
> 
> Any updates on this fic will happen on my Instagram!
> 
> IG: nasta.fics


	2. Amaranthus - Hopelessness

**Summary for the Chapter:**

> Asta finds out about Hanahaki.

**Notes for the Chapter:**

> 'Sup y'all. This fic is gonna get a decent amount of new chapters soon. Prepare yourselves for a very unique take on Hanahaki. Enjoy~

In retrospect, it was _really_ obvious he had Hanahaki.

On the day of the attack on the Royal Capital, he was coughing like crazy. It was a miracle he didn’t have a fit while he and Yuno were talking to the Wizard King.

When Asta stood up to those arrogant Magic Knights at the rank ceremony, his lungs decided to betray him at an inopportune time. The member of the Golden Dawn that was taunting him used the moment of weakness to pin him to the table he was standing on with a giant fist of sand.

“I knew it. You’re just a weak kid with no magic and a big mouth. Go back to your garbage squad. You don’t belong here.”

He was about to pop off on the asshole in front of him when he caught a glimpse of Yuno in the corner of his eye. The wind mage was leaned casually against the wall with his arms crossed. He looked apathetic, like he couldn’t care less about the situation before him.

_Like he couldn’t care less about Asta._

The two made eye contact with each other from across the room. Asta was still pinned down. Yuno was still showing no sign that he cared. No sign, concern, or worry for his friend of fifteen years.

Asta felt like he had to vomit.

It was an excruciating sensation. One he would feel countless times over in varying degrees of pain during his time fighting the disease. He remembered the first one feeling like a sharp ache in all of his torso, almost as though his lungs were an active volcano ready to burst out piping hot magma into the rest of his body and out through his mouth.

The coughing fit that followed was violent. It only subsided after someone had come bursting into the room to frantically announce that the Royal Capital was being invaded. By the end of his speech, everyone was too busy trying to organize themselves and prepare a plan of action that his wheezing was largely forgotten about.

One person remembered though.

They were about to break up into their small groups and head to their designated parts of the city when a pale hand gently landed on his shoulder. 

“You should get that cough looked at once this is all over. Don’t let it distract you during a real fight. You wouldn’t be much of a rival if you ended up dead.”

Asta felt his cheeks get red and his palms get clammy. The way Yuno looked at him, with his golden eyes lit up and his lips quirked the slightest bit up, was breathtaking. The warm hand touching him seemed to magically alleviate some of the pain in his throat and chest. 

_Yuno went out of his way to talk to him and make sure he was okay._

Asta nodded enthusiastically, grinning like the lovesick fool he was. The special attention from his newly realized crush was making his heart beat faster with every passing second and he couldn’t trust his raspy voice to not cut out in the middle of a sentence. Plus, there was no time to talk.

They had a city to save.

* * *

Asta was doing pretty good at not coughing. Until he wasn’t.

It was after Fuegoleon had interfered in his fight against the corpse magic guy and the charismatic fire mage came back from the enemy’s portal missing an arm.

Asta couldn’t believe it. Right in front of his eyes, the third ever person to express their faith in him and take him seriously (the first was Yuno, the second was Captain Yami) was dropped like trash and defeated like nothing.

It made him feel like all hope was lost. He was already tired and weak from the zombie guy’s curse, and if someone as strong as Fuegoleon was wiped out so quickly, how was he supposed to stand a chance? If he couldn’t do something as simple as protecting the citizens of Clover Kingdom, how was he going to become the Wizard King, a symbol of the strength and safety of their kingdom?

How was Yuno supposed to keep his faith in him?

All the air in Asta’s lungs was ripped away and his legs gave out. Thankfully, his fast reflexes kicked in and he used his swords to prop himself up before he could fall. He wretched out cough after cough, feeling like something was clogging the back of his throat and he had to get it _out_.

The enemy wasn’t making a move on him just yet, instead focusing on Leopold, but he knew that wouldn’t last long. It was just a matter of time before they would all be killed.

_“You should get that cough looked at once this is all over. Don’t let it distract you during a real fight. You wouldn’t be much of a rival if you ended up dead.”_

Asta’s eyes, which were closed shut from the painful coughs, suddenly shot open.

He couldn’t die here. He couldn’t let some stupid cough get the better of him. He had someone to live for, and a goal to work towards.

Fuck curses.

Asta sliced through the cursed parts of his body with his two swords, effectively erasing them with antimagic.

“I’m not going down yet! No matter what happens, I can’t give up now! It’s not like the odds were ever in my favor to begin with, so bring it on!!!”

And then he went and got himself kidnapped.

It always had to be him, huh?

* * *

Seeing the Wizard King fight the Eye of the Midnight Sun was as inspiring as it was terrifying. Asta had a lot of work ahead of him if he ever hoped to reach Julius’ level of power. He was basically useless the entire time, and he was starting to cough again.

Julius had finished fighting and was in the middle of explaining why the Royal Capital was attacked and what the Midnight Sun was after when Asta’s cough escalated once again. The only difference was that this time he was finally able to cough out the thing that had been lodged in his throat since the beginning of the day.

Asta coughed out a mouthful of tiny red petals and screamed.

“WHAT THE HELL?! WHAT IS HAPPENING TO ME?” He looked at the Wizard King in genuine horror and was the tiniest bit relieved when Julius didn’t freak out and recognition seemed to shine in his eyes.

“It would seem you’ve caught a case of lovesickness.”

“Huh?” Was Asta’s smart reply.

“Its official name is Hanahaki Disease, but most have referred to it as ‘lovesickness’. Hanahaki is how the concept of dying from a broken heart made its way into fairytales, but it’s extremely rare, so you’ve probably never learned about it, or have seen anyone ill from it.”

“But how can being sick make me cough flower petals?”

“The term ‘disease’ or ‘illness’ is actually a misnomer. Hanahaki isn’t caused by bacteria or any kind of virus. It isn’t contagious either. Hanahaki Disease is a magical illness that’s similar to a curse, except it has no caster. It forms entirely on its own. There were very few recorded cases of it, but from what I’ve read, Hanahaki is tied to feelings of love and affection."

"So how does this thing work?"

"My personal theory is that the magic of our loved ones reacts to our emotions, and when someone experiences the distress of unrequited love strongly enough, small bits of their magic attach themselves in the other person’s chest to soothe their pain. However, since it’s foreign magic, your body’s cells attack it to get rid of it, but instead, the magic uses those cells to grow and take the form of plant magic. If left untreated, it can slowly result in the failure of your lungs and cause death. It’s all very complicated, but I can give you some more detailed information once we’re back in the capital. Do you have any questions?”

“So you’re saying this curse thingy can KILL me?”

“Only if it isn’t treated regularly.”

“What’s the treatment?”

“Love.”

“Are you kidding?”

“Not at all. You need frequent and positive exposure to the person you love. Their affection is the only known ‘cure’, but unless you feel truly and completely loved, your Hanahaki will never go away. The effects will just be suppressed until the next time you feel lovesick. I recommend you dedicate at least one day every week to meeting with Yuno to make sure your condition doesn’t worsen.”

“Wait a second, how did you know I loved Yuno?! We’ve only known you for a day!” Asta said with a small blush dusting his cheeks.

“Oh come on, it’s _extremely_ obvious.”

“Fine Mister Smarty Pants Wizard King, answer me this. Why did Yuno’s magic form these little red petals? Why wasn’t it any other flower petal?”

“Oh! That’s a very good question. It’s thought the type of flower is directly affected by the emotions you felt before coughing it out. Depending on what you feel, it can change from day to day.”

“What do these red ones mean then? I’ve never seen them before,” Asta held a small bunch of the petals in his hands, poking them around with his finger curiously. Julius frowned the slightest bit and his eyes looked at Asta with a sad softness.

“From the look of them, I’d say they’re the petals of the amaranthus flower. It’s more commonly known by the nickname love-lies-bleeding because it’s petals grow downward in a tail shape and look like someone’s guts pouring out of their body.” The tall blond man paused to touch Asta's shoulder in a comforting gesture.

“It represents _hopelessness._ ”

**Notes for the Chapter:**

> How did you like my explanation? I love trying to embed the lore of the show into whatever AU I'm writing. That being said, since my version of Hanahaki will be a bit different from others, feel free to ask questions in the comments and I'll do my best to answer them!
> 
> Comments are always welcome!
> 
> IG: natsa.fics


	3. Yellow Hyacinth - Jealousy

**Summary for the Chapter:**

> Asta wants to be strong.

**Notes for the Chapter:**

> This chapter had a mind of its own. Hope you enjoy reading it!

Asta had no idea just how much the Wizard King knew about Hanahaki until he heaved a giant binder (it was half his size) full of scientific reports and various pictures of flowers.

Julius had kindly brought him back to the Royal Capital and after he made an official announcement about the attack, he directed Asta to join him in his office to talk more about his condition. He sent the other Noelle and Miss Charmy to check up on the town’s citizens as a useful distraction so they could talk privately.

”Just how long have you been researching Hanahaki?” Asta asked.

“By now, I’d say I’ve spent the better part of five years compiling information and gathering what little primary and secondary sources are out there,” he responded.

“Why?”

“Simply because it’s fun to learn about!” Julius said excitedly.

“But aren’t you busy? Don’t you, like, run the kingdom?” Julius merely waved his hand, dismissing Asta’s (very valid) question altogether and continued speaking.

“I have lots of information, but most of what’s in this binder are my personal findings and speculation. That being said, my theories are far from fiction. I’ve collected and condensed most of my information on Hanahaki in this small booklet for ease of use. I’m sure you’ll find it useful,” the mage handed Asta a thin booklet he pulled from inside one of the folders of the binder. It had a plain brown paper covering devoid of writing on the outside. However, when he flipped through it he was met with countless colorful pictures of all types of flowers, their petals, their names, and their individual meanings.

“Woah. Uh. Thank you, Mister Wizard King.” While he expressed his gratitude awkwardly, Asta was genuinely thankful for the man’s help.

“No problem. I just ask that you keep in mind just how much work went into creating that small book, and I’m just letting you know that if anything bad happens to it I will be very sad.”

“I’ll try my very best to keep it safe, sir!” Asta stood up and saluted for good measure.

“Good. Now before you go, I want to tell you about an idea that just occurred to me.”

“What is it?”

“A theory about another possible cure for your Hanahaki.”

* * *

Asta was deep in thought when he met back up with Noelle and Charmy. He didn’t know what to think about what Julius had told him. Luckily his teammates were there to distract him. Charmy had apparently met the man of her dreams while fighting, and her story was a comforting distraction. So much so that it distracted him from where he was going and they ended up lost (not that he knew where he was going in the first place, but they didn’t need to know that).

The silver-haired boy turned his head to find out where the hell they were and caught sight of the very person plaguing his thoughts.

“Yuno! Hey!” Asta called out while waving his arms to catch his crush’s attention. He was with Mimosa and Klaus, presumably also leaving to go back to their squad’s base.

Yuno responded with a blank stare and utter silence.

_Don’t let it get to you. That’s just how he normally is._

“It’s not nice to ignore people, Yuno! Can’t you ever talk to me like a normal person?” Asta shouted once more.

The attack on his life made by a giant wind falcon further proved that Yuno had serious communication issues.

One swing of his demon slayer sword later and Asta was _fuming._

“What the hell was that for?!!” As the winged beast dissolved, the wind magic it was made of seemed to reform before Asta’s very eyes. Yuno’s magic control must have improved during the fighting, but Yuno’s improvement wasn’t anything unexpected. What was unexpected, however, was the message itself.

**_“Did you check that cough yet?”_ **

Once Asta read it, all the annoyance he felt towards Yuno at that moment vanished. In his own (admittedly very strange and slightly violent) way, he was checking up on Asta. A bright smile slowly crept upon his face until it became a full-blown grin. He felt the sudden need to talk to Yuno face to face (up until then Asta had been looking up at him from a lower section of ground and a river separated him from Yuno’s section). So, like he always did, Asta did something rash and stupid without thinking about the potential consequences.

“Catch me!” Asta yelled as he ran and jumped for the elevated street Yuno and his teammates were standing on. He only made it halfway there before he started falling, but he trusted in Yuno to do the rest. Sure enough, a platform of dense air was there to catch him and raise him up, leaving Asta at exactly eye level with Yuno.

“Idiot. There was a bridge right there,” was the first thing to leave Yuno’s lips throughout their entire exchange. The boy gestured toward a bridge Asta definitely hadn’t seen before, but the silver-haired agent of chaos tried to play it off.

“This was faster,” Asta argued.

“...”

_You won’t ignore me that easily!_

“I wanted to tell you that I got my cough looked at,” Asta continued.

“You could have done it from down there.” Yuno looked bored with his antics.

“Didn’t want to.”

“So? You’re not dying are you?” Yuno asked.

 _Not yet,_ Asta wanted to morbidly respond, but he held his tongue. Yuno didn’t need any reason to bring Asta’s health into question and he certainly didn’t need to know about his Hanahaki. Death only happened after a long time of fighting it. Asta could deal with it on his own without Yuno having to worry about him.

“Nah, Doc said it’s because you’re a handsome emo bastard and don’t like talking to me. Said I have to visit you until you appreciate me and then my cough will go away.” It was only a small white lie. In fact, the least truthful part of his story was calling the Wizard King a doctor, and even that wasn’t too far off the beaten path. Julius certainly had the brains for it.

“Very funny, short stack. Are you seriously okay though?” Good. Yuno took it as a joke.

“I’m fine. I do seriously want to visit you sometimes though.”

“I might be on a mission when you come.”

“That’s fine. I’ll drop by sometimes anyway.”

“Fine.” That simple four-letter word was all Asta needed to hear. He would be fine. It would all be fine. He would still see Yuno. He would get his Hanahaki under control. He wouldn’t die.

Asta left the Royal Capital with a soft smile and a heart full of hope.

* * *

Asta was having a good afternoon. He was relaxing with his squad mates in the common room, listening to Charmy tell them all about her knight in shining armor, feeling reassured after his conversation with Yuno. He had gotten lost trying to find where everyone was and joined in the middle of her story. Asta was mostly zoned out, as he had heard the part she was telling to everyone back in the city. He only perked up and really started listening when Charmy mentioned him by name.

“And then when we were all heading back, we ran into him on the street! He was so handsome and cool. Asta was talking to him, but I couldn’t say anything because I was too embarrassed. Yuno was so dreamy, la~,” she said.

Asta’s blood ran cold.

Did he just hear that right? The person Miss Charmy was so enamored with was Yuno, of all people? It had to have been the guy he was in love with?

An ugly feeling settled into the pit of Asta’s stomach. It was dark and seething, something he had never felt with such a burning intensity before.

He had known Yuno for fifteen years. They had grown up together. Yuno’s never been as close to anyone as he is with him. Charmy can’t just waltz in and claim Yuno for herself! Charmy didn’t know Yuno like Asta did.

_No one can take Yuno away from me like that._

Asta unconsciously fisted his hands in the fabric of his pants, hunching over so nobody could see the anger blatantly displayed on his face. He ground his teeth together as he kept listening to Charmy go on and on about how pretty and perfect Yuno was, even going as far as running through imaginary scenarios of them being a couple.

She just liked him for his looks. She didn’t understand who he was under his silent exterior. She didn’t know him. She had no right to love him!

_Neither do you._

Asta’s whole body flinched at his intrusive thought, and it made him take a step back from all the negative feelings pouring out of him. 

What right did _he_ have? Yuno wasn’t his boyfriend and it wasn’t like he belonged to anyone. Asta had no right to invalidate Charmy’s emotions just because he didn’t like who they were directed towards. If he really thought about, Charmy was probably a way better fit for Yuno. She was sweet and strong. Not to mention she was a _girl,_ and while Yuno hadn’t expressed any romantic interest in anyone _ever,_ Asta thought it was safe to assume he didn’t bat for the same team.

Asta was probably the farthest thing from what Yuno wanted from a lover.

The feeling in his stomach seemed to travel up to his chest, making his heart beat erratically. He gasped quietly, desperately trying to force air into his lungs and fight off the flower petals he knew were about to come up. Panic flooded Asta’s body as he rushed to lift himself off the couch he was sitting on and ran toward where the bathroom had been earlier. He just prayed it hadn’t moved throughout the day.

Asta wrapped his hands around his neck in a vain attempt to slow down the rising of the petals in his throat once he was safely out of sight. Thankfully, the bathroom was right where he remembered it being, and he frantically pulled one of his hands away from his neck to yank the door open and close it shut behind him. He had just barely made it to the toilet before the pressure was too much to handle and he coughed up spit-soaked yellow petals into the white porcelain bowl.

He must have been coughing for two whole minutes before he managed to get all the petals out. His eyes were watering from the sheer amount of pain that came with every cough. These petals were larger than the red ones he had vomited up earlier. They hurt so much more to get out. Asta flushed them all except for one, which he twirled between his fingers as he wiped a stray string of saliva from his chin.

No one seemed to suspect anything was wrong. They hadn’t come to check on him, so he guessed they all thought he had to take a dump all of a sudden. That was fine with him. His teammates didn’t need to know about his hopeless crush. Especially Charmy. He was strong. He could deal with this on his own.

Asta decided he didn’t want to go back to the common room. He had enough reminders of Yuno for one day, so he turned in the opposite direction from whence he came and headed to his room. He wanted to be alone, and it was late anyway. No one would be surprised if he left to go to bed.

After he locked his door, Asta pulled out the booklet Julius had given him and searched for the bright yellow petal held between his fingertips. It took a while, but he eventually found it. It was the petal of a Yellow Hyacinth. He whispered the description of its meaning quietly to himself.

“The Yellow Hyacinth’s meaning stems from an ancient myth about a boy named Hyakinthos. He was the object of both the sun god’s and the west wind’s affection. The west wind challenged the sun god to a disc throwing competition to win the boy’s affection, as he was closer to the sun god. To ensure his victory, the west wind heightened the strength of the wind when the sun god threw his disc, but it ended up flying toward Hyakinthos, hitting him on the head and killing him. This is why the Yellow Hyacinth represents _jealousy_.”

**Notes for the Chapter:**

> The story at the end is loosely based on a Greek myth. Very dramatic stuff. This chapter was a fun one to write. I left the little mystery of what Julius' theory was, feel free to make a guess as to what it was in the comments. Thanks for reading~
> 
> IG: natsa.fics


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